The majority of power boats in use today use either gasoline or diesel fuel. Reasonable prudence, and U.S. Coast Guard requirements, stipulate that the tanks used to store such fuels should be made as safe as possible from fire and explosion hazards. The tanks must be rugged enough to resist leakage after being subjected to the vibration and other motion of motor boat operation, and must be properly sealed to prevent the volatile vapors of the fuels from escaping exterior the tank.
Fuel tanks made of cross linked polyethylene have become popular in the boating industry. The polyethylene tanks are quite resistant to vibration and impact. Further, the polyethylene tanks will not rust or degrade in service. Typically, UVI stabilizers are incorporated in the polyethylene to resist degradation from ultra violet rays from the sun.
Naturally, some access is necessary through the wall of the tank to fill the tank with fuel and remove the fuel for use by the engine. Furthermore, many installations require the use of a visual fuel level gauge or fuel gauge sender as well. In certain applications, a metal access plate has been molded into the polyethylene tank to provide the various fittings and ports for these purposes. However, in use, the polyethylene swells, frequently breaking the seal formed between the polyethylene material and the metal plate and destroying the integrity of the tank. In other applications, threaded apertures have actually been formed through the wall of the polyethylene tank to receive fittings. However, during use, these threaded apertures will often be stripped and necessitate the replacement of the entire tank.
A need exists for an improved system to access a fuel tank of this type which is inexpensive, reliable and provides a secure seal to prevent the fuel vapors from escaping the tank.